qgsexpressionbuilderwidget.h

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/***************************************************************************
    qgisexpressionbuilderwidget.h - A generic expression builder widget.
     --------------------------------------
    Date                 :  29-May-2011
    Copyright            : (C) 2011 by Nathan Woodrow
    Email                : woodrow.nathan at gmail dot com
 ***************************************************************************
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/
 
#ifndef QGSEXPRESSIONBUILDER_H
#define QGSEXPRESSIONBUILDER_H
 
#include "ui_qgsexpressionbuilder.h"
 
#include "qgis_gui.h"
#include "qgis_sip.h"
#include "qgsexpression.h"
#include "qgsexpressioncontext.h"
#include "qgsexpressiontreeview.h"
 
#include <QSortFilterProxyModel>
#include <QStandardItemModel>
#include <QString>
#include <QWidget>
 
using namespace Qt::StringLiterals;
 
class QgsFields;
class QgsExpressionHighlighter;
class QgsRelation;
class QgsCodeEditorExpression;
 
#ifndef SIP_RUN
static const QString DEFAULT_PROJECT_FUNCTIONS_ITEM_NAME = u"[Project Functions]"_s;
#endif

class GUI_EXPORT QgsExpressionBuilderWidget : public QWidget, private Ui::QgsExpressionBuilderWidgetBase
{
    Q_OBJECT
  public:
    enum Flag SIP_ENUM_BASETYPE( IntFlag )
    {
      LoadNothing = 0,                            
      LoadRecent = 1 << 1,                        
      LoadUserExpressions = 1 << 2,               
      LoadAll = LoadRecent | LoadUserExpressions, 
    };
    Q_DECLARE_FLAGS( Flags, Flag )
    Q_FLAG( Flag )
 
 
    
    QgsExpressionBuilderWidget( QWidget *parent SIP_TRANSFERTHIS = nullptr );
    ~QgsExpressionBuilderWidget() override;

    void init( const QgsExpressionContext &context = QgsExpressionContext(), const QString &recentCollection = u"generic"_s, QgsExpressionBuilderWidget::Flags flags = LoadAll );

    void initWithLayer(
      QgsVectorLayer *layer, const QgsExpressionContext &context = QgsExpressionContext(), const QString &recentCollection = u"generic"_s, QgsExpressionBuilderWidget::Flags flags = LoadAll
    );

    void initWithFields(
      const QgsFields &fields, const QgsExpressionContext &context = QgsExpressionContext(), const QString &recentCollection = u"generic"_s, QgsExpressionBuilderWidget::Flags flags = LoadAll
    );

    void setLayer( QgsVectorLayer *layer );

    QgsVectorLayer *layer() const;

    Q_DECL_DEPRECATED void loadFieldNames() SIP_DEPRECATED {}

    Q_DECL_DEPRECATED void loadFieldNames( const QgsFields &fields ) SIP_DEPRECATED { mExpressionTreeView->loadFieldNames( fields ); }

    Q_DECL_DEPRECATED void loadFieldsAndValues( const QMap<QString, QStringList> &fieldValues ) SIP_DEPRECATED;

    void setGeomCalculator( const QgsDistanceArea &da );

    QString expressionText();

    void setExpressionText( const QString &expression );

    QString expectedOutputFormat();

    void setExpectedOutputFormat( const QString &expected );

    QgsExpressionContext expressionContext() const { return mExpressionContext; }

    void setExpressionContext( const QgsExpressionContext &context );

    bool isExpressionValid();
 
#ifndef SIP_RUN

    void setCustomPreviewGenerator( const QString &label, const QList<QPair<QString, QVariant>> &choices, const std::function<QgsExpressionContext( const QVariant & )> &previewContextGenerator );
#else

    void setCustomPreviewGenerator( const QString &label, const QList<QPair<QString, QVariant>> &choices, SIP_PYCALLABLE );
    //%MethodCode
    Py_XINCREF( a2 );
    Py_BEGIN_ALLOW_THREADS sipCpp->setCustomPreviewGenerator( *a0, *a1, [a2]( const QVariant &value ) -> QgsExpressionContext {
      QgsExpressionContext res;
      SIP_BLOCK_THREADS
      PyObject *s = sipCallMethod( NULL, a2, "D", &value, sipType_QVariant, NULL );
      int state;
      int sipIsError = 0;
      QgsExpressionContext *t1 = reinterpret_cast<QgsExpressionContext *>( sipConvertToType( s, sipType_QgsExpressionContext, 0, SIP_NOT_NONE, &state, &sipIsError ) );
      if ( sipIsError == 0 )
      {
        res = QgsExpressionContext( *t1 );
      }
      sipReleaseType( t1, sipType_QgsExpressionContext, state );
      SIP_UNBLOCK_THREADS
      return res;
    } );
 
    Py_END_ALLOW_THREADS
    //%End
#endif
 

    Q_DECL_DEPRECATED void saveToRecent( const QString &collection = "generic" ) SIP_DEPRECATED;

    Q_DECL_DEPRECATED void loadRecent( const QString &collection = u"generic"_s ) SIP_DEPRECATED;

    QgsExpressionTreeView *expressionTree() const;

    Q_DECL_DEPRECATED void loadUserExpressions() SIP_DEPRECATED;

    Q_DECL_DEPRECATED void saveToUserExpressions( const QString &label, const QString &expression, const QString &helpText ) SIP_DEPRECATED;

    Q_DECL_DEPRECATED void removeFromUserExpressions( const QString &label ) SIP_DEPRECATED;

    void newFunctionFile( const QString &fileName = "scratch" );

    void saveFunctionFile( QString fileName );

    void loadCodeFromFile( QString path );

    void loadCodeFromProjectFunctions();

    void loadFunctionCode( const QString &code );

    void updateFunctionFileList( const QString &path );

    void saveProjectFunctionsEntry();

    Q_DECL_DEPRECATED QStandardItemModel *model() SIP_DEPRECATED;

    QgsProject *project();

    void setProject( QgsProject *project );

    bool evalError() const;

    bool parserError() const;

    void setExpressionPreviewVisible( bool isVisible );
 
  public slots:

    void loadSampleValues();

    void loadAllValues();

    void loadSampleUsedValues();

    void loadAllUsedValues();

    void autosave();

    void setAutoSave( bool enabled ) { mAutoSave = enabled; }

    void storeCurrentUserExpression();

    void removeSelectedUserExpression();

    void editSelectedUserExpression();

    const QList<QgsExpressionItem *> findExpressions( const QString &label );
 
 
  private slots:
    void indicatorClicked( int line, int index, Qt::KeyboardModifiers state );
    void onExpressionParsed( bool state );
    void expressionTreeItemChanged( QgsExpressionItem *item );
    void operatorButtonClicked();
    void commentLinesClicked();
    void btnRun_pressed();
    void btnNewFile_pressed();
    void btnRemoveFile_pressed();

    void exportUserExpressions_pressed();

    void importUserExpressions_pressed();
    void cmbFileNames_currentItemChanged( QListWidgetItem *item, QListWidgetItem *lastitem );
    void insertExpressionText( const QString &text );
    void txtExpressionString_textChanged();
    void txtSearchEditValues_textChanged();
    void mValuesListView_doubleClicked( const QModelIndex &index );
    void txtPython_textChanged();
 
  signals:

    void expressionParsed( bool isValid );

    void evalErrorChanged();

    void parserErrorChanged();
 
  protected:
    void showEvent( QShowEvent *e ) override;
 
  private:
    class ExpressionTreeMenuProvider : public QgsExpressionTreeView::MenuProvider
    {
      public:
        ExpressionTreeMenuProvider( QgsExpressionBuilderWidget *expressionBuilderWidget )
          : QgsExpressionTreeView::MenuProvider()
          , mExpressionBuilderWidget( expressionBuilderWidget )
        {}
 
        QMenu *createContextMenu( QgsExpressionItem *item ) override;
 
      private:
        QgsExpressionBuilderWidget *mExpressionBuilderWidget;
    };
 
    int FUNCTION_MARKER_ID = 25;
 
    void createErrorMarkers( const QList<QgsExpression::ParserError> &errors );
    void createMarkers( const QgsExpressionNode *node );
    void clearFunctionMarkers();
    void clearErrors();
    void runPythonCode( const QString &code );
    void displayTemporaryLabel( const QString &text );
    QgsVectorLayer *contextLayer( const QgsExpressionItem *item ) const;
    void fillFieldValues( const QString &fieldName, QgsVectorLayer *layer, int countLimit, bool forceUsedValues = false );
    QString getFunctionHelp( QgsExpressionFunction *function );
    QString loadFunctionHelp( QgsExpressionItem *functionName );
    QString helpStylesheet() const;
 
    // To be called whenever expression context has been updated
    void expressionContextUpdated();
 
    // Will hold items with
    // * a display string that matches the represented field values
    // * custom data in Qt::UserRole + 1 that contains a ready to use expression literal ('quoted string' or NULL or a plain number )
    std::unique_ptr<QStandardItemModel> mValuesModel;
    std::unique_ptr<QSortFilterProxyModel> mProxyValues;
 
    ExpressionTreeMenuProvider *mExpressionTreeMenuProvider = nullptr;
 
    bool mAutoSave = true;
    QString mFunctionsPath;
    QgsVectorLayer *mLayer = nullptr;
    bool mExpressionValid = false;
    QgsExpressionContext mExpressionContext;
    QPointer<QgsProject> mProject;
 
    // Translated name of the user expressions group
    QString mUserExpressionsGroupName;
 
    QgsCodeEditorExpression *txtExpressionString = nullptr;
};
 
// clazy:excludeall=qstring-allocations
 
#endif // QGSEXPRESSIONBUILDER_H